Anaerobic Digestion : Anaergia to build State-of-the-art food waste and wastewater sludge co-digestion facility at Monterey One Water

Monterey One Water Anaergia
© Anaergia

Anaergia has announced that it will provide technologies that will enable Monterey One Water, the wastewater utility of northern Monterey County, California, to produce renewable energy from both food waste and wastewater.

The project will significantly expand the anaerobic digestion capacity at Monterey One Water's Regional Treatment Plant (RTP) in Marina, California, and provide organic waste receiving and pre-processing equipment. This will allow the utility to receive and co-digest food waste in existing digesters currently used to process wastewater biosolids. The anaerobic digestion of the waste will produce renewable biogas, which will be used to generate electricity and heat at the Monterey One facility.

Like our content? Subscribe to our newsletters!

Improve performance and save energy

The project will bring a mothballed anaerobic digester back into service and provide state-of-the-art Anaergia digestion tank-mixing technology to process food waste with biosolids without impacting critical wastewater operations. The new technology will simultaneously improve performance and save energy. In addition to the ability to co-digest food waste with biosolids, Monterey One will benefit from a significant expansion of digester capacity to provide operational flexibility.

The project will increase biogas production from the plant's four digesters by more than 150%, which will be used to generate up to 1.6 MW of renewable electricity through on-site combined heat and power (CHP) engines. The increased energy production will meet more than 100% of the plant's energy needs, significantly reducing operating costs, supporting revenue generation and increasing resilience and reliability. This significant expansion of on-site energy generation is a key asset in the development of a shared microgrid that will be used by Monterey One's neighbour and the regional waste management agency, ReGen.

Advance compliance with California law

The upgraded anaerobic digestion technologies and new waste receiving facilities will support the region's solid waste industry by enabling the diversion of food waste from regional landfills to advance compliance with California's SB1383 legislation. The new law aims to reduce planet-warming methane emissions from the landfilling of food and other organic waste.

CalRecycle, California's Department of Resources Recycling and Recovery, will provide $4,218,900 in grant funding, minimising the impact on the utility's ratepayers by offsetting the majority of the project costs. Work on the project is expected to begin in Q2 2023 and be completed by Q3 2024.